Celebrating the 68000

Stand back in awe and guard your vital organs as James Matson hurls a few powerhouse words of vintage gaming at you.  Ready? Nintendo, Sega, Atari, Commodore, Motorola.

Wait, what? Motorola? Didn’t they make mobile phones?

That last one might have raised the eyebrows of the unwashed masses, but Motorola (now split into Motorola Mobility & Motorola Solutions) lived under the plastic and buttons of several well known consoles and its 68000 CPU were intrinsically linked with the rise of gaming in the home.  The 68000 was a CISC (Complex Instruction Set) processor with sixteen 32-bit registers and a 16-bit data bus and a rampaging clock speed of 8MHz.  The whole 32-bit/16-bit combination made the 68000 a difficult chip to categorize into a bit ‘class’ as such, while it could address 32-bits, it could only do so through a 16-bit bus, generally speaking though, it appears history is content to label the 68000 a 32-bit CPU.

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But the quirks of its architecture or the quaint transistor count (68,000 versus the 820 million of your average Intel Q9650) are not the reason to celebrate its existence, instead it’s the fact that this little chip was under the hood of so many well loved gaming machines. A bulk of the first Amiga computer models had a 7.14MHz 68000 powering them, including the 1000, 500, 600, 2000 and CDTV.  The Megadrive/Genesis – Sega’s most successful console – was powered by the vintage grunt of the 68000, not to mention a host of arcade boards/systems like the Neo Geo, System 16 and Capcom’s CPS/CPS-2 (which means some of the most popular arcade games in history were delivered via the 68000’s single digit megahertz).  While not utilised at the main CPU in the Sega Saturn, the 68000 nonetheless had a role as the Saturn’s sound controller.

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Even the Atari Jaguar – already fully staffed with two 32-bit RISC processors – featured a Motorola 68000 chip, which Atari claimed was to give developers familiarity early on when developing for the platform.  The idea worked, a little too well according to bits and pieces floating around the ‘net – with developers actually preferring to write code for the known 68000 than the RISC architecture.  Sounds fine in theory, but who knows how much the 68000 leaning might have crippled the Jaguar’s potential?  It certainly didn’t help the architecture, as all three chips shared the same unified data bus and when the 68000 was accessing it, the other – more sophisticated processors – couldn’t.

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Feeling the 68000 love right now? If you are, you can grab the programmer’s manual from here and get fully down to the nuts and bolts of the architecture. You nerd.